Perpetual-adding slate and key.



W. B. HERBERT.

PBRPBTUAL ADDING SLATBANDKEY.

APPLICATION FILED DEO. 21, 1909.

Batented May 30 27.737 QLUVVIZIO 5 ffaaof Z 3.75am? Mac a 90575 563007.?2.99067 275335 zego .WILLIAM '.B. HERBERT, 0F WEST NUTLEY, NEW JERSEY.

yEBPETUAL-ADDING vSIIA'IE AND KEY.

Specification of Letters Patent.

Patented May 30, 1911.

` Application led December 21, 1909. Serial No. 534,253.

To all whom 'it may concern:

Be it known that I, WILLIAM B. HERBERT, a subject of the King of GreatBritain, and a resident of West hutley, county of- Essex, and State ofNew Jersey, have invented certain new and` useful Improvements inPerpetual-Adding Slates and Keys, of which the following is a full,clear, and exact description.

This invention relates to an education appliance adapted to assist inthe instruction of addition.

The primary object of the invention is to provide a simple device whichwill display various columns of figures in a designated space togetherwith means for determining the sum Atotal of said columns. N

A- further .object of the invention is to produce a device that willarrange various columns of figures in proper alinement to be added by astudent.

lVith these and other objects in view, the invention will be hereinaftermore .partie` ularly described with reference to the accompanyingdrawings, which form a part of this specification, and will then bepointed out in the claims at the end of the description.

Figure 1 is a front elevation of the device.-

Fig. 2 is an elevation of a key chart constituting a feature of myinvention. Fig. 8 is a section on the line III--IIL is a section on aline IV-IV and Fig. 5 is a section on the line V-V.

.In the drawing, 10 designates a casing consisting of three members 11,12 and 13 secured to each other at their edge portions. These membersare so positioned as to provide a space between each outer member andthe centrall member. f A plurality of rectangular members 1,2, 3, and 4-are inserted between the inner'member and the member- 11,l said membersbeing arranged one above the other. Each of these members is adapted toslide back and forth between the two members 11 and 12. Each slidingmember is provided with ve rows of numerals the Fig. 4 l

The longitudinalv set of five columns. of figures theV sliding f membersare moved until said set appears in the vertical slot. Each set of fivenumbers is designated by a dierent numeral in the lower right handcorner and by referring to this numeral the instructor may designate thepartieularcolumn to be added. Thus after if it is desired to add acertain setof columns on each slidev it will only be necessary for theinstructor to state what lower right hand figure should be in each set.rlhis arrangement it will be seen will do away with they necessity ofcalling 0E each numeral in the entire set. The slides are termed 1, 2, 3and 4 and referred to by their numbers as the designating numeral in thelower right hand corner is given.' This means will allow an unlimitednumber of combinations of'numerals to be arranged for addition.

The numerals upon the strips 1, 2, 3 and 4 are so placed that the sum ofany group of five numbers will always be thesame when the lower righthand figure of the group is the same, and the totals on the key chartare previously ascertained by adding.

- The totals in column No. 1a in Fig. 2 re resent the sums of the groupof' ve num ers on slide 1 for each ten numerals, that is for each of thetennumerals from O to 9, as the right hand lower numeral of the group offive. 2b represent the sums of the group of five numbers on slide 2,&c., the totals varying The totals in the column No. f

with the variation of the lower right hand figure of each" group offivenumbers.

In Fig. 1 in the drawing it will be seen that 'the slides are set sothat series 2 will ap- .pear on the first slide, series 3 on the secondslide, series 5 on the third slide, 'and series 4 on the fourth slide,therefore in instructing a student to add the five columns offigures-displayed it would be necessary for the instructor to merelydesignate series 2 slide 1 series 3 slide 2, etc. On the opposite faceof the device are arranged four members 20 heading Na 3c andso on.

to correspond with the number of slides on the reverse side. Thesemembers are numbered l, 2b, 3, and 4d, and said members consist ofstrips of card-board or'other material provided with recesses to supportthe member 21 which is adapted to slide over the face of said strips. Oneach of the stationary members are arranged rows of numerals, each rowof numerals being numbered to correspond with the lower right handfigure on one of the sliding members 1, 2, 3 and 4. Each set of numeralsof the rows on the stationary key represents the sum total of one of thegroups of numerals on the slides 1 to 4. For exam le the totals on thekey under the heading No. 3o represent the sums of the group of figureson slide 3. In the illustration given the Alower right hand number ofthe group of figures on slide 3 is 5, and the figures on the key underNo. 3c numbered 5 represent the total of the figures shown on slide 3 inFig. 1 or 196557. If the lower right hand numeral onslide 3 were 9, the`sum of the group of figures on said strip 3 would be 299,067, as thatnumber appears under the designation 9 on the key under the As beforestated the stationary members l, 2", 3c and fl are numbered tocorrespond with the sliding members 1, 2, 3 ande; and the` total of thevarious sets of gures on slide 1 are arranged upon the stationary memberNo. 1a. Each total bears the same figure as that which appears in thelower right hand cor-l ner of the set of numerals of which the same 1sthe sum total. These numbers are arranged above the sum total. It willtherefore be seen that if the numeral 2'appears in is only-necessary toadd the four sets of g-.

the lower right hand corner of slide 1 the set of numerals designated by2 under the heading No. 1a on the stationary member will be the sumtotal of the ve columns of figures displayed on slide 1 when it is inthe position shown. The slide 21 is for the purpose of locating thevarious lines of figures on the stationary member. A ground glass member22 is located at the bottom of the stationary members on which the sumtotal may be written. To ascertain the sum total of all of the four setsdisplayed by slides 1, 2, 3, 4, it

ures which re resent the s um total ofeach set, therefore 1t will beseen that the sum of twenty rows of fgures'may be ascertained by addinfour rows of fi res.

In igs. 1, 3, 4, and 5 the adding mechanism which we will term the keyis shown as an integral part of the means for displaying the gures to beadded but this form of' device is intended only for the use of theinstructor as it is desired that the student find the sum total byadding the columns displayed. A separate device as shown in Fi 2 may besupplied to the student to veriiy his work after he has performed thevarious sums in addition. This device consists of a member 23 providedwith slots 24 through which the slides 25 are inserted.

The many advantages of a device of this nature will be clearly apparent,rst it is a quick method of giving outwork to a student, second thestudents time is saved by not having to copy the sum to be added, andthird it provides a means whereby the student or instructor caninstantaneously ascertain the correct solution to the problems given.

Having thus described my invention I claim as new and desire to secureby Letters Patent 1. device of the character described comprising acasing consisting of a front formed with'a slot, a plurality of slotstrans- ,verse to said first mentioned slot, a back, and a series ofslides between said frontA and back each bearing a plurality of rows ofalined characters and exposed through said iirst mentioned slot, saidtransverse slots serving to expose portions of said slides to facilitatetheir being moved.

2. An adding-device comprising a casing consisting of a front."lA formedwith a vertical slot, and a plurality of horizontal slots', a back, anda series of slides between said front and back each bearing a pluralityof rows of vertically-alined numerals constituting a problem in additionand exposed through said vertical slot, said horizontal slots serving toexpose portions of said slides to facilitate their being moved.

' 3. An adding device comprising a casing formed with vertical andhorizontal slots, horizontally movable slides within said casing.bearing vertically alined groups of numerals, -and being adapted to beexposed through said slots, and a key bearing numerals representingthesum totals of the groups of numerals on the slides.

This specification signed andJ witnessed this 18th day of December A. D.1909.

WILLIAM B. HERBERT.

Witnesses:

lW. A. ToWNnR, Jr.,

M. DINNHAUPT.

